Computer readable storage medium containing code for automated collection and analysis of patient information retrieved from an implantable medical device for remote patient care

ABSTRACT

A computer readable storage medium containing code for automated collection and analysis of patient information retrieved from a medical device adapted to be implanted in a patient for remote patient care is described. A set of collected measures is periodically received from the medical device adapted to be implanted over a communications link which is interfaced to a network server. The collected measures set includes individual measures which each relate to patient information recorded by the medical device adapted to be implanted for an individual patient. The collected measures set is stored into a patient care record for the individual patient within a database server organized to store one or more patient care records. Each patient care record includes a plurality of the collected measures sets. One or more of the collected measures sets in the patient care record for the individual patient is analyzed relative to one or more other collected measures sets stored in the database server to determine a patient status indicator.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This patent application is a divisional of U.S. patentapplication, Ser. No. 09/789,456, filed Feb. 20, 2001, pending, which isa divisional of U.S. patent application, Ser. No. 09/324,894, filed Jun.3, 1999, pending, the priority dates of which are claimed and thedisclosures of which are incorporated by reference.

FIELD OF THE INVENTION

[0002] The present invention relates in general to automated datacollection and analysis, and, in particular, to a computer readablestorage medium containing code for automated collection and analysis ofpatient information retrieved from an implantable medical device forremote patient care.

BACKGROUND OF THE INVENTION

[0003] Implantable pulse generators (IPGs) are medical devices commonlyused to treat irregular heartbeats, known as arrhythmias. There are twobasic types. Cardiac pacemakers are used to manage bradycardia, anabnormally slow or irregular heartbeat. Left untreated, bradycardia cancause symptoms such as fatigue, dizziness, and fainting. Implantablecardioverter defibrillators (ICDs) are used to treat tachycardia, heartrhythms that are abnormally fast and life threatening. Tachycardia canresult in sudden cardiac death (SCD).

[0004] Pacemakers and ICDs are increasingly being equipped with anon-board, volatile memory in which telemetered signals can be stored forlater retrieval and analysis. Typically, the telemetered signals providepatient device information regarding atrial electrical activity,ventricular electrical activity, time of day, activity level, cardiacoutput, oxygen level, cardiovascular pressure measures, pulmonarymeasures, and any interventions made on a per heartbeat or binnedaverage basis. In addition, a growing class of cardiac medical devices,including implantable heart failure monitors, implantable eventmonitors, cardiovascular monitors, and therapy devices, are being usedto provide similar stored device information. These devices are able tostore approximately thirty minutes of per heartbeat data. Telemeteredsignals are also stored in a broader class of monitors and therapeuticdevices for other areas of medicine, including metabolism,endocrinology, hematology, neurology, muscular, gastrointestinal,genitalurology, ocular, auditory, and the like.

[0005] Presently, stored device information is retrieved using aproprietary interrogator or programmer, often during a clinic visit orfollowing a device event. The volume of data retrieved from a singledevice interrogation “snapshot” can be large and proper interpretationand analysis can require significant physician time and detailedsubspecialty knowledge, particularly by cardiologists and cardiacelectrophysiologists. The sequential logging and analysis of regularlyscheduled interrogations can create an opportunity for recognizingsubtle and incremental changes in patient condition otherwiseundetectable by inspection of a single “snapshot.” However, presentapproaches to data interpretation and understanding and practicallimitations on time and physician availability make such analysisimpracticable.

[0006] A prior art system for collecting and analyzing pacemaker and ICDtelemetered signals in a clinical or office setting is the Model 9790Programmer, manufactured by Medtronic, Inc., Minneapolis, Minn. Thisprogrammer can be used to retrieve data, such as patientelectrocardiogram and any measured physiological conditions, collectedby the IPG for recordation, display and printing. The retrieved data isdisplayed in chronological order and analyzed by a physician. Comparableprior art systems are available from other IPG manufacturers, such asthe Model 2901 Programmer Recorder Monitor, manufactured by GuidantCorporation, Indianapolis, Ind., which includes a removable floppydiskette mechanism for patient data storage. These prior art systemslack remote communications facilities and must be operated with thepatient present. These systems present a limited analysis of thecollected data based on a single device interrogation and lack thecapability to recognize trends in the data spanning multiple episodesover time or relative to a disease specific peer group.

[0007] A prior art system for locating and communicating with a remotemedical device implanted in an ambulatory patient is disclosed in U.S.Pat. No. 5,752,976 ('976). The implanted device includes a telemetrytransceiver for communicating data and operating instructions betweenthe implanted device and an external patient communications device. Thecommunications device includes a communication link to a remote medicalsupport network, a global positioning satellite receiver, and a patientactivated link for permitting patient initiated communication with themedical support network.

[0008] Related prior art systems for remotely communicating with andreceiving telemetered signals from a medical device are disclosed inU.S. Pat. Nos. 5,113,869 ('869) and 5,336,245 ('245). In the '869patent, an implanted AECG monitor can be automatically interrogated atpreset times of day to telemeter out accumulated data to a telephoniccommunicator or a full disclosure recorder. The communicator can beautomatically triggered to establish a telephonic communication link andtransmit the accumulated data to an office or clinic through a modem. Inthe '245 patent, telemetered data is downloaded to a larger capacity,external data recorder and is forwarded to a clinic using an auto-dialerand fax modem operating in a personal computer-basedprogrammer/interrogator. However, the '976 telemetry transceiver, '869communicator, and '245 programmer/interrogator are limited tofacilitating communication and transferal of downloaded patient data anddo not include an ability to automatically track, recognize, and analyzetrends in the data itself.

[0009] Thus, there is a need for a system and method for providingcontinuous retrieval, transferal, and automated analysis of retrievedimplantable medical device information, such as telemetered signals,retrieved in general from a broad class of implantable medical devicesand, in particular, from IPGs and cardiovascular monitors. Preferably,the automated analysis would include recognizing a trend and determiningwhether medical intervention is necessary.

[0010] There is a further need for a system and method that would allowconsideration of sets of collected measures, both actual and derived,from multiple device interrogations. These collected measures sets couldthen be compared and analyzed against short and long term periods ofobservation.

[0011] There is a further need for a system and method that would enablethe measures sets for an individual patient to be self-referenced andcross-referenced to similar or dissimilar patients and to the generalpatient population. Preferably, the historical collected measures setsof an individual patient could be compared and analyzed against those ofother patients in general or of a disease specific peer group inparticular.

SUMMARY OF THE INVENTION

[0012] The present invention provides a computer readable storage mediumcontaining code for automated collection and analysis of patientinformation retrieved from an implantable medical device for remotepatient care. The patient device information relates to individualmeasures recorded by and retrieved from implantable medical devices,such as IPGs and monitors. The patient device information is received ona regular, e.g., daily, basis as sets of collected measures which arestored along with other patient records in a database. The informationcan be analyzed in an automated fashion and feedback provided to thepatient at any time and in any location.

[0013] An embodiment of the present invention is a computer-readablestorage medium holding code for automated collection and analysis ofpatient information retrieved from a medical device adapted to beimplanted in a patient for remote patient care. A set of collectedmeasures is periodically received from the medical device adapted to beimplanted over a communications link which is interfaced to a networkserver. The collected measures set includes individual measures whicheach relate to patient information recorded by the medical deviceadapted to be implanted for an individual patient. The collectedmeasures set is stored into a patient care record for the individualpatient within a database server organized to store one or more patientcare records. Each patient care record includes a plurality of thecollected measures sets. One or more of the collected measures sets inthe patient care record for the individual patient is analyzed relativeto one or more other collected measures sets stored in the databaseserver to determine a patient status indicator. The patient statusindicators are then triaged and prioritized for an appropriate level ofalert and interaction.

[0014] The present invention facilitates the gathering, storage, andanalysis of critical patient information obtained on a routine basis andanalyzed in an automated manner. Thus, the burden on physicians andtrained personnel to evaluate the volumes of information issignificantly minimized while the benefits to patients are greatlyenhanced.

[0015] Still other embodiments of the present invention will becomereadily apparent to those skilled in the art from the following detaileddescription, wherein is described embodiments of the invention by way ofillustrating the best mode contemplated for carrying out the invention.As will be realized, the invention is capable of other and differentembodiments and its several details are capable of modifications invarious obvious respects, all without departing from the spirit and thescope of the present invention. Accordingly, the drawings and detaileddescription are to be regarded as illustrative in nature and not asrestrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016]FIG. 1 is a block diagram showing a system for automatedcollection and analysis of patient information retrieved from animplantable medical device for remote patient care in accordance withthe present invention;

[0017]FIG. 2 is a block diagram showing the hardware components of theserver system of the system of FIG. 1;

[0018]FIG. 3 is a block diagram showing the software modules of theserver system of the system of FIG. 1;

[0019]FIG. 4 is a block diagram showing the analysis module of theserver system of FIG. 3; FIG. 5 is a database schema showing, by way ofexample, the organization of a cardiac patient care record stored in thedatabase of the system of FIG. 1;

[0020]FIG. 6 is a record view showing, by way of example, a set ofpartial cardiac patient care records stored in the database of thesystem of FIG. 1;

[0021]FIG. 7 is a flow diagram showing a method for automated collectionand analysis of patient information retrieved from an implantablemedical device for remote patient care in accordance with the presentinvention;

[0022]FIG. 8 is a flow diagram showing a routine for analyzing collectedmeasures sets for use in the method of FIG. 7;

[0023]FIG. 9 is a flow diagram showing a routine for comparing siblingcollected measures sets for use in the routine of FIG. 8;

[0024]FIGS. 10A and 10B are flow diagrams showing a routine forcomparing peer collected measures sets for use in the routine of FIG. 8;and

[0025]FIG. 11 is a flow diagram showing a routine for providing feedbackfor use in the method of FIG. 7.

DETAILED DESCRIPTION

[0026]FIG. 1 is a block diagram showing a system 10 for automatedcollection and analysis of patient information retrieved from animplantable medical device for remote patient care in accordance withthe present invention. A patient 11 is a recipient of an implantablemedical device 12, such as, by way of example, an IPG or a heart failureor event monitor, with a set of leads extending into his or her heart.The implantable medical device 12 includes circuitry for recording intoa short-term, volatile memory telemetered signals, which are stored as aset of collected measures for later retrieval.

[0027] For an exemplary cardiac implantable medical device, thetelemetered signals non-exclusively present patient information relatingto: atrial electrical activity, ventricular electrical activity, time ofday, activity level, cardiac output, oxygen level, cardiovascularpressure measures, the number and types of interventions made, and therelative success of any interventions made on a per heartbeat or binnedaverage basis, plus the status of the batteries and prograrnmedsettings. Examples of pacemakers suitable for use in the presentinvention include the Discovery line of pacemakers, manufactured byGuidant Corporation, Indianapolis, Ind. Examples of ICDs suitable foruse in the present invention include the Ventak line of ICDs, alsomanufactured by Guidant Corporation, Indianapolis, Ind.

[0028] In the described embodiment, the patient 11 has a cardiacimplantable medical device. However, a wide range of related implantablemedical devices are used in other areas of medicine and a growing numberof these devices are also capable of measuring and recording patientinformation for later retrieval. These implantable medical devicesinclude monitoring and therapeutic devices for use in metabolism,endocrinology, hematology, neurology, muscularology,gastro-intestinalogy, genital-urology, ocular, auditory, and similarmedical subspecialties. One skilled in the art would readily recognizethe applicability of the present invention to these related implantablemedical devices.

[0029] On a regular basis, the telemetered signals stored in theimplantable medical device 12 are retrieved. By way of example, aprogrammer 14 can be used to retrieve the telemetered signals. However,any form of programmer, interrogator, recorder, monitor, or telemeteredsignals transceiver suitable for communicating with an implantablemedical device 12 could be used, as is known in the art. In addition, apersonal computer or digital data processor could be interfaced to theimplantable medical device 12, either directly or via a telemeteredsignals transceiver configured to communicate with the implantablemedical device 12.

[0030] Using the programmer 14, a magnetized reed switch (not shown)within the implantable medical device 12 closes in response to theplacement of a wand 13 over the location of the implantable medicaldevice 12. The programmer 14 communicates with the implantable medicaldevice 12 via RF signals exchanged through the wand 14. Programming orinterrogating instructions are sent to the implantable medical device 12and the stored telemetered signals are downloaded into the programmer14. Once downloaded, the telemetered signals are sent via aninternetwork 15, such as the Internet, to a server system 16 whichperiodically receives and stores the telemetered signals in a database17, as further described below with reference to FIG. 2.

[0031] An example of a programmer 14 suitable for use in the presentinvention is the Model 2901 Programmer Recorder Monitor, manufactured byGuidant Corporation, Indianapolis, Ind., which includes the capabilityto store retrieved telemetered signals on a proprietary removable floppydiskette. The telemetered signals could later be electronicallytransferred using a personal computer or similar processing device tothe internetwork 15, as is known in the art.

[0032] Other alternate telemetered signals transfer means could also beemployed. For instance, the stored telemetered signals could beretrieved from the implantable medical device 12 and electronicallytransferred to the internetwork 15 using the combination of a remoteexternal programmer and analyzer and a remote telephonic communicator,such as described in U.S. Pat. No. 5,113,869, the disclosure of which isincorporated herein by reference. Similarly, the stored telemeteredsignals could be retrieved and remotely downloaded to the server system16 using a world-wide patient location and data telemetry system, suchas described in U.S. Pat. No. 5,752,976, the disclosure of which isincorporated herein by reference.

[0033] The received telemetered signals are analyzed by the serversystem 16, which generates a patient status indicator. The feedback isthen provided back to the patient 11 through a variety of means. By wayof example, the feedback can be sent as an electronic mail messagegenerated automatically by the server system 16 for transmission overthe internetwork 15. The electronic mail message is received by personalcomputer 18 (PC) situated for local access by the patient 11.Alternatively, the feedback can be sent through a telephone interfacedevice 19 as an automated voice mail message to a telephone 21 or as anautomated facsimile message to a facsimile machine 22, both alsosituated for local access by the patient 11. In addition to a personalcomputer 18, telephone 21, and facsimile machine 22, feedback could besent to other related devices, including a network computer, wirelesscomputer, personal data assistant, television, or digital dataprocessor. Preferably, the feedback is provided in a tiered fashion, asfurther described below with reference to FIG. 3.

[0034]FIG. 2 is a block diagram showing the hardware components of theserver system 16 of the system 10 of FIG. 1. The server system 16consists of three individual servers: network server 31, database server34, and application server 35. These servers are interconnected via anintranetwork 33. In the described embodiment, the functionality of theserver system 16 is distributed among these three servers for efficiencyand processing speed, although the functionality could also be performedby a single server or cluster of servers. The network server 31 is theprimary interface of the server system 16 onto the internetwork 15. Thenetwork server 31 periodically receives the collected telemeteredsignals sent by remote implantable medical devices over the internetwork15. The network server 31 is interfaced to the internetwork 15 through arouter 32. To ensure reliable data exchange, the network server 31implements a TCP/IP protocol stack, although other forms of networkprotocol stacks are suitable.

[0035] The database server 34 organizes the patient care records in thedatabase 17 and provides storage of and access to information held inthose records. A high volume of data in the form of collected measuressets from individual patients is received. The database server 34 freesthe network server 31 from having to categorize and store the individualcollected measures sets in the appropriate patient care record.

[0036] The application server 35 operates management applications andperforms data analysis of the patient care records, as further describedbelow with reference to FIG. 3. The application server 35 communicatesfeedback to the individual patients either through electronic mail sentback over the internetwork 15 via the network server 31 or as automatedvoice mail or facsimile messages through the telephone interface device19.

[0037] The server system 16 also includes a plurality of individualworkstations 36 (WS) interconnected to the intranetwork 33, some ofwhich can include peripheral devices, such as a printer 37. Theworkstations 36 are for use by the data management and programmingstaff, nursing staff, office staff, and other consultants and authorizedpersonnel.

[0038] The database 17 consists of a high-capacity storage mediumconfigured to store individual patient care records and related healthcare information. Preferably, the database 17 is configured as a set ofhigh-speed, high capacity hard drives, such as organized into aRedundant Array of Inexpensive Disks (RAID) volume. However, any form ofvolatile storage, non-volatile storage, removable storage, fixedstorage, random access storage, sequential access storage, permanentstorage, erasable storage, and the like would be equally suitable. Theorganization of the database 17 is further described below withreference to FIG. 3.

[0039] The individual servers and workstations are general purpose,programmed digital computing devices consisting of a central processingunit (CPU), random access memory (RAM), non-volatile secondary storage,such as a hard drive or CD ROM drive, network interfaces, and peripheraldevices, including user interfacing means, such as a keyboard anddisplay. Program code, including software programs, and data are loadedinto the RAM for execution and processing by the CPU and results aregenerated for display, output, transmittal, or storage. In the describedembodiment, the individual servers are Intel Pentium-based serversystems, such as available from Dell Computers, Austin, Tex., or CompaqComputers, Houston, Tex. Each system is preferably equipped with 128 MBRAM, 100 GB hard drive capacity, data backup facilities, and relatedhardware for interconnection to the intranetwork 33 and internetwork 15.In addition, the workstations 36 are also Intel Pentium-based personalcomputer or workstation systems, also available from Dell Computers,Austin, Tex., or Compaq Computers, Houston, Tex. Each workstation ispreferably equipped with 64 MB RAM, 10 GB hard drive capacity, andrelated hardware for interconnection to the intranetwork 33. Other typesof server and workstation systems, including personal computers,minicomputers, mainframe computers, supercomputers, parallel computers,workstations, digital data processors and the like would be equallysuitable, as is known in the art.

[0040] The telemetered signals are communicated over an internetwork 15,such as the Internet. However, any type of electronic communicationslink could be used, including an intranetwork link, serial link, datatelephone link, satellite link, radio-frequency link, infrared link,fiber optic link, coaxial cable link, television link, and the like, asis known in the art. Also, the network server 31 is interfaced to theinternetwork 15 using a T-1 network router 32, such as manufactured byCisco Systems, Inc., San Jose, Calif. However, any type of interfacingdevice suitable for interconnecting a server to a network could be used,including a data modem, cable modem, network interface, serialconnection, data port, hub, frame relay, digital PBX, and the like, asis known in the art.

[0041]FIG. 3 is a block diagram showing the software modules of theserver system 16 of the system 10 of FIG. 1. Each module is a computerprogram written as source code in a conventional programming language,such as the C or Java programming languages, and is presented forexecution by the CPU as object or byte code, as is known in the arts.The various implementations of the source code and object and byte codescan be held on a computer-readable storage medium or embodied on atransmission medium in a carrier wave. There are three basic softwaremodules, which functionally define the primary operations performed bythe server system 16: database module 51, analysis module 53, andfeedback module 55. In the described embodiment, these modules areexecuted in a distributed computing environment, although a singleserver or a cluster of servers could also perform the functionality ofthe modules. The module functions are further described below in moredetail beginning with reference to FIG. 7.

[0042] For each patient being provided remote patient care, the serversystem 16 periodically receives a collected measures set 50 which isforwarded to the database module 51 for processing. The database module51 organizes the individual patent care records stored in the database52 and provides the facilities for efficiently storing and accessing thecollected measures sets 50 and patient data maintained in those records.An exemplary database schema for use in storing collected measures sets50 in a patient care record is described below, by way of example, withreference to FIG. 5. The database server 34 (shown in FIG. 2) performsthe functionality of the database module 51. Any type of databaseorganization could be utilized, including a flat file system,hierarchical database, relational database, or distributed database,such as provided by database vendors, such as Oracle Corporation,Redwood Shores, Calif.

[0043] The analysis module 53 analyzes the collected measures sets 50stored in the patient care records in the database 52. The analysismodule 53 makes an automated determination of patient wellness in theform of a patient status indicator 54. Collected measures sets 50 areperiodically received from implantable medical devices and maintained bythe database module 51 in the database 52. Through the use of thiscollected information, the analysis module 53 can continuously followthe medical well being of a patient and can recognize any trends in thecollected information that might warrant medical intervention. Theanalysis module 53 compares individual measures and derived measuresobtained from both the care records for the individual patient and thecare records for a disease specific group of patients or the patientpopulation in general. The analytic operations performed by the analysismodule 53 are further described below with reference to FIG. 4. Theapplication server 35 (shown in FIG. 2) performs the functionality ofthe analysis module 53.

[0044] The feedback module 55 provides automated feedback to theindividual patient based, in part, on the patient status indicator 54.As described above, the feedback could be by electronic mail or byautomated voice mail or facsimile. Preferably, the feedback is providedin a tiered manner. In the described embodiment, four levels ofautomated feedback are provided. At a first level, an interpretation ofthe patient status indicator 54 is provided. At a second level, anotification of potential medical concern based on the patient statusindicator 54 is provided. This feedback level could also be coupled withhuman contact by specially trained technicians or medical personnel. Ata third level, the notification of potential medical concern isforwarded to medical practitioners located in the patient's geographicarea. Finally, at a fourth level, a set of reprogramming instructionsbased on the patient status indicator 54 could be transmitted directlyto the implantable medical device to modify the programming instructionscontained therein. As is customary in the medical arts, the basic tieredfeedback scheme would be modified in the event of bona fide medicalemergency. The application server 35 (shown in FIG. 2) performs thefunctionality of the feedback module 55.

[0045]FIG. 4 is a block diagram showing the analysis module 53 of theserver system 16 of FIG. 3. The analysis module 53 contains twofunctional submodules: comparison module 62 and derivation module 63.The purpose of the comparison module 62 is to compare two or moreindividual measures, either collected or derived. The purpose of thederivation module 63 is to determine a derived measure based on one ormore collected measures which is then used by the comparison module 62.For instance, a new and improved indicator of impending heart failurecould be derived based on the exemplary cardiac collected measures setdescribed with reference to FIG. 5. The analysis module 53 can operateeither in a batch mode of operation wherein patient status indicatorsare generated for a set of individual patients or in a dynamic modewherein a patient status indicator is generated on the fly for anindividual patient.

[0046] The comparison module 62 receives as inputs from the database 17two input sets functionally defined as peer collected measures sets 60and sibling collected measures sets 61, although in practice, thecollected measures sets are stored on a per sampling basis. Peercollected measures sets 60 contain individual collected measures setsthat all relate to the same type of patient information, for instance,atrial electrical activity, but which have been periodically collectedover time. Sibling collected measures sets 61 contain individualcollected measures sets that relate to different types of patientinformation, but which may have been collected at the same time ordifferent times. In practice, the collected measures sets are notseparately stored as “peer” and “sibling” measures. Rather, eachindividual patient care record stores multiple sets of sibling collectedmeasures. The distinction between peer collected measures sets 60 andsibling collected measures sets 61 is further described below withreference to FIG. 6.

[0047] The derivation module 63 determines derived measures sets 64 onan as-needed basis in response to requests from the comparison module62. The derived measures 64 are determined by performing linear andnon-linear mathematical operations on selected peer measures 60 andsibling measures 61, as is known in the art.

[0048]FIG. 5 is a database schema showing, by way of example, theorganization of a cardiac patient care record stored 70 in the database17 of the system 10 of FIG. 1. Only the information pertaining tocollected measures sets are shown. Each patient care record would alsocontain normal identifying and treatment profile information, as well asmedical history and other pertinent data (not shown). Each patient carerecord stores a multitude of collected measures sets for an individualpatient. Each individual set represents a recorded snapshot oftelemetered signals data which was recorded, for instance, per heartbeator binned average basis by the implantable medical device 12. Forexample, for a cardiac patient, the following information would berecorded as a collected measures set: atrial electrical activity 71,ventricular electrical activity 72, time of day 73, activity level 74,cardiac output 75, oxygen level 76, cardiovascular pressure measures 77,pulmonary measures 78, interventions made by the implantable medicaldevice 78, and the relative success of any interventions made 80. Inaddition, the implantable medical device 12 would also communicatedevice specific information, including battery status 81 and programsettings 82. Other types of collected measures are possible. Inaddition, a welldocumented set of derived measures can be determinedbased on the collected measures, as is known in the art.

[0049]FIG. 6 is a record view showing, by way of example, a set ofpartial cardiac patient care records stored in the database 17 of thesystem 10 of FIG. 1. Three patient care records are shown for Patient 1,Patient 2, and Patient 3. For each patent, three sets of measures areshown, X, Y, and Z. The measures are organized into sets with Set 0representing sibling measures made at a reference time t=0. Similarly,Set n-2, Set n-1 and Set n each represent sibling measures made at laterreference times t=n-2, t=n-1 and t=n, respectively.

[0050] For a given patient, for instance, Patient 1, all measuresrepresenting the same type of patient information, such as measure X,are peer measures. These are measures, which are monitored over time ina disease-matched peer group. All measures representing different typesof patient information, such as measures X, Y, and Z, are siblingmeasures. These are measures which are also measured over time, butwhich might have medically significant meaning when compared to eachother within a single set. Each of the measures, X, Y, and Z. could beeither collected or derived measures.

[0051] The analysis module 53 (shown in FIG. 4) performs two basic formsof comparison. First, individual measures for a given patient can becompared to other individual measures for that same patient. Thesecomparisons might be peer-to-peer measures projected over time, forinstance, X_(n), X_(n-1), X_(n-2), . . . X₀, or sibling-to-siblingmeasures for a single snapshot, for instance, X_(n), Y_(n), and Z_(n),or projected over time, for instance, X_(n), Y_(n), Z_(n), X_(n-1),Y_(n-1), Z_(n-1), X_(n-2), Y_(n-2), Z_(n-2), . . . X₀, Y₀, Z₀. Second,individual measures for a given patient can be compared to otherindividual measures for a group of other patients sharing the samedisease-specific characteristics or to the patient population ingeneral. Again, these comparisons might be peer-to-peer measuresprojected over time, for instance, X_(n), X_(n′), X_(n″), X_(n-1),X_(n-1′), X_(n-1″), X_(n-2), X_(n-2′), X_(n-2″). . . X₀, X_(0′), X_(0″),or comparing the individual patient's measures to an average from thegroup. Similarly, these comparisons might be sibling-to-sibling measuresfor single snapshots, for instance, X_(n), X_(n′), X_(n″), Y_(n),Y_(n′), Y_(n″), and Z_(n), Z_(n′), Z_(n″), or projected over time, forinstance, X_(n), X_(n′), X_(n″), Y_(n), Y_(n′), Y_(n″), Z_(n), Z_(n′),Z_(n″), X_(n-1), X_(n-1′), X_(n-1″), Y_(n-1),Y_(n-1′), Y_(n-1″),Z_(n-1), Z_(n-1′), Z_(n-1″), X_(n-2), X_(n-2′), X_(n-2″), Y_(n-2),Y_(n-2′), Y_(n-2″), Z_(n-2), Z_(n-2′), Z_(n-2″), . . . X₀, X_(0′),X_(0″), Y₀, Y_(0′), Y_(0″), and Z₀, Z_(0′), Z_(0″). Other forms ofcomparisons are feasible.

[0052]FIG. 7 is a flow diagram showing a method 90 for automatedcollection and analysis of patient information retrieved from animplantable medical device 12 for remote patient care in accordance withthe present invention. The method 90 is implemented as a conventionalcomputer program for execution by the server system 16 (shown in FIG.1). As a preparatory step, the patient care records are organized in thedatabase 17 with a unique patient care record assigned to eachindividual patient (block 91). Next, the collected measures sets for anindividual patient are retrieved from the implantable medical device 12(block 92) using a programmer, interrogator, telemetered signalstransceiver, and the like. The retrieved collected measures sets aresent, on a substantially regular basis, over the internetwork 15 orsimilar communications link (block 93) and periodically received by theserver system 16 (block 94). The collected measures sets are stored intothe patient care record in the database 17 for that individual patient(block 95). One or more of the collected measures sets for that patientare analyzed (block 96), as further described below with reference toFIG. 8. Finally, feedback based on the analysis is sent to that patientover the internetwork 15 as an email message, via telephone line as anautomated voice mail or facsimile message, or by similar feedbackcommunications link (block 97), as further described below withreference to FIG. 11.

[0053]FIG. 8 is a flow diagram showing the routine for analyzingcollected measures sets 96 for use in the method of FIG. 7. The purposeof this routine is to make a determination of general patient wellnessbased on comparisons and heuristic trends analyses of the measures, bothcollected and derived, in the patient care records in the database 17. Afirst collected measures set is selected from a patient care record inthe database 17 (block 100). If the measures comparison is to be made toother measures originating from the patient care record for the sameindividual patient (block 101), a second collected measures set isselected from that patient care record (block 102). Otherwise, a groupmeasures comparison is being made (block 101) and a second collectedmeasures set is selected from another patient care record in thedatabase 17 (block 103). Note the second collected measures set couldalso contain averaged measures for a group of disease specific patientsor for the patient population in general.

[0054] Next, if a sibling measures comparison is to be made (block 104),a routine for comparing sibling collected measures sets is performed(block 105), as further described below with reference to FIG. 9.Similarly, if a peer measures comparison is to be made (block 106), aroutine for comparing sibling collected measures sets is performed(block 107), as further described below with reference to FIGS. 10A and10B.

[0055] Finally, a patient status indicator is generated (block 108). Byway of example, cardiac output could ordinarily be approximately 5.0liters per minute with a standard deviation of ±1.0. An actionablemedical phenomenon could occur when the cardiac output of a patient is±3.0-4.0 standard deviations out of the norm. A comparison of thecardiac output measures 75 (shown in FIG. 5) for an individual patientagainst previous cardiac output measures 75 would establish the presenceof any type of downward health trend as to the particular patient. Acomparison of the cardiac output measures 75 of the particular patientto the cardiac output measures 75 of a group of patients would establishwhether the patient is trending out of the norm. From this type ofanalysis, the analysis module 53 generates a patient status indicator 54and other metrics of patient wellness, as is known in the art.

[0056]FIG. 9 is a flow diagram showing the routine for comparing siblingcollected measures sets 105 for use in the routine of FIG. 8. Siblingmeasures originate from the patient care records for an individualpatient. The purpose of this routine is either to compare siblingderived measures to sibling derived measures (blocks 111-113) or siblingcollected measures to sibling collected measures (blocks 115-117). Thus,if derived measures are being compared (block 110), measures areselected from each collected measures set (block 111). First and secondderived measures are derived from the selected measures (block 112)using the derivation module 63 (shown in FIG. 4). The first and secondderived measures are then compared (block 113) using the comparisonmodule 62 (also shown in FIG. 4). The steps of selecting, determining,and comparing (blocks 111-113) are repeated until no further comparisonsare required (block 114), whereupon the routine returns.

[0057] If collected measures are being compared (block 110), measuresare selected from each collected measures set (block 115). The first andsecond collected measures are then compared (block 116) using thecomparison module 62 (also shown in FIG. 4). The steps of selecting andcomparing (blocks 115-116) are repeated until no further comparisons arerequired (block 117), whereupon the routine returns.

[0058]FIGS. 10A and 10B are a flow diagram showing the routine forcomparing peer collected measures sets 107 for use in the routine ofFIG. 8. Peer measures originate from patient care records for differentpatients, including groups of disease specific patients or the patientpopulation in general. The purpose of this routine is to compare peerderived measures to peer derived measures (blocks 122-125), peer derivedmeasures to peer collected measures (blocks 126-129), peer collectedmeasures to peer derived measures (block 131-134), or peer collectedmeasures to peer collected measures (blocks 135-137). Thus, if the firstmeasure being compared is a derived measure (block 120) and the secondmeasure being compared is also a derived measure (block 121), measuresare selected from each collected measures set (block 122). First andsecond derived measures are derived from the selected measures (block123) using the derivation module 63 (shown in FIG. 4). The first andsecond derived measures are then compared (block 124) using thecomparison module 62 (also shown in FIG. 4). The steps of selecting,determining, and comparing (blocks 122-124) are repeated until nofurther comparisons are required (block 115), whereupon the routinereturns.

[0059] If the first measure being compared is a derived measure (block120) but the second measure being compared is a collected measure (block121), a first measure is selected from the first collected measures set(block 126). A first derived measure is derived from the first selectedmeasure (block 127) using the derivation module 63 (shown in FIG. 4).The first derived and second collected measures are then compared (block128) using the comparison module 62 (also shown in FIG. 4). The steps ofselecting, determining, and comparing (blocks 126-128) are repeateduntil no further comparisons are required (block 129), whereupon theroutine returns.

[0060] If the first measure being compared is a collected measure (block120) but the second measure being compared is a derived measure (block130), a second measure is selected from the second collected measuresset (block 131). A second derived measure is derived from the secondselected measure (block 132) using the derivation module 63 (shown inFIG. 4). The first collected and second derived measures are thencompared (block 133) using the comparison module 62 (also shown in FIG.4). The steps of selecting, determining, and comparing (blocks 131-133)are repeated until no further comparisons are required (block 134),whereupon the routine returns.

[0061] If the first measure being compared is a collected measure (block120) and the second measure being compared is also a collected measure(block 130), measures are selected from each collected measures set(block 135). The first and second collected measures are then compared(block 136) using the comparison module 62 (also shown in FIG. 4). Thesteps of selecting and comparing (blocks 135-136) are repeated until nofurther comparisons are required (block 137), whereupon the routinereturns.

[0062]FIG. 11 is a flow diagram showing the routine for providingfeedback 97 for use in the method of FIG. 7. The purpose of this routineis to provide tiered feedback based on the patient status indicator.Four levels of feedback are provided with increasing levels of patientinvolvement and medical care intervention. At a first level (block 150),an interpretation of the patient status indicator 54, preferably phrasedin lay terminology, and related health care information is sent to theindividual patient (block 151) using the feedback module 55 (shown inFIG. 3). At a second level (block 152), a notification of potentialmedical concern, based on the analysis and heuristic trends analysis, issent to the individual patient (block 153) using the feedback module 55.At a third level (block 154), the notification of potential medicalconcern is forwarded to the physician responsible for the individualpatient or similar health care professionals (block 155) using thefeedback module 55. Finally, at a fourth level (block 156),reprogramming instructions are sent to the implantable medical device 12(block 157) using the feedback module 55.

[0063] Therefore, through the use of the collected measures sets, thepresent invention makes possible immediate access to expert medical careat any time and in any place. For example, after establishing andregistering for each patient an appropriate baseline set of measures,the database server could contain a virtually up-to-date patienthistory, which is available to medical providers for the remotediagnosis and prevention of serious illness regardless of the relativelocation of the patient or time of day.

[0064] Moreover, the gathering and storage of multiple sets of criticalpatient information obtained on a routine basis makes possible treatmentmethodologies based on an algorithmic analysis of the collected datasets. Each successive introduction of a new collected measures set intothe database server would help to continually improve the accuracy andeffectiveness of the algorithms used. In addition, the present inventionpotentially enables the detection, prevention, and cure of previouslyunknown forms of disorders based on a trends analysis and by across-referencing approach to create continuously improving peer-groupreference databases.

[0065] Finally, the present invention makes possible the provision oftiered patient feedback based on the automated analysis of the collectedmeasures sets. This type of feedback system is suitable for use in, forexample, a subscription based health care service. At a basic level,informational feedback can be provided by way of a simple interpretationof the collected data. The feedback could be built up to provide agradated response to the patient, for example, to notify the patientthat he or she is trending into a potential trouble zone. Humaninteraction could be introduced, both by remotely situated and localmedical practitioners. Finally, the feedback could include directinterventive measures, such as remotely reprogramming a patient's IPG.

[0066] While the invention has been particularly shown and described asreferenced to the embodiments thereof, those skilled in the art willunderstand that the foregoing and other changes in form and detail maybe made therein without departing from the spirit and scope of theinvention.

What is claimed is:
 1. A computer-readable storage medium containingcode for automated remote patient care using patient informationretrieved from a medical device adapted to be implanted in a patient,comprising: organizing one or more patient care records in a databasewith each patient care record comprising a plurality of the collectedmeasurements sets, each collected measurements set comprising individualmeasurements which each relate to patient information recorded by amedical device adapted to be implanted for an individual patient;receiving a set of the collected measurements periodically sent from theimplantable medical device over a communications link; storing thecollected measurements set into the patient care record in the databasefor the individual patient; analyzing one or more of the collectedmeasurements sets in the patient care record for the individual patientrelative to one or more other collected measurements sets stored in thepatient care record of the individual patient; and sending feedbackbased on the analysis of the one or more collected measurements sets tothe individual patient over a feedback communications link.
 2. A storagemedium according to claim 1, the operation of analyzing furthercomprising: comparing at least one collected measurement selected fromthe one or more collected measurements sets to at least one othercollected measurement selected from the one or more other collectedmeasurements sets, the at least one collected measurement and the atleast one other collected measurement both relating to the same type ofpatient information.
 3. A storage medium according to claim 1, theoperation of analyzing further comprising: comparing at least onecollected measurement selected from the one or more collectedmeasurements sets to at least one other collected measurement selectedfrom the one or more other collected measurements sets, the at least onecollected measurement and the at least one other collected measurementboth relating to different types of patient information.
 4. A storagemedium according to claim 1, the operation of analyzing furthercomprising: determining at least one derived measurement using at leastone collected measurement selected from at least one of the one or morecollected measurements sets and the one or more other collectedmeasurements sets; and comparing the at least one derived measurement toat least one measurement selected from at least one of the one or morecollected measurements sets and the one or more other collectedmeasurements sets.
 5. A storage medium according to claim 1, theoperation of analyzing further comprising: determining at least onederived measurement using at least one collected measurement selectedfrom at least one of the one or more collected measurements sets and theone or more other collected measurements sets; determining at least oneother derived measurement using at least one collected measurementselected from at least one of the one or more collected measurementssets and the one or more other collected measurements sets; andcomparing the at least one derived measurement to the at least one otherderived measurement.
 6. A storage medium according to claim 1, theoperation of sending feedback further comprising: providing tieredfeedback comprising: at a first level of feedback, communicating aninterpretation of the analysis of the one or more collected measurementssets to the individual patient over the feedback communications link; ata second level of feedback, communicating a notification of potentialmedical concern based on the analysis of the one or more collectedmeasurements sets to the individual patient over the feedbackcommunications link; at a third level of feedback, communicating anotification of potential medical concern based on the analysis of theone or more collected measurements sets to medical personnel in localproximity to the individual patient over the feedback communicationslink; and at a fourth level of feedback, communicating a set ofreprogramming instructions based on analysis of the one or morecollected measurements sets to the implantable medical device over thefeedback communications link.